I. Field of the Invention
The present invention relates generally to the fields of pharmaceutical compositions to be used in treatments, such as, sleeping disorders, such as, e.g., narcolepsy (particularly cataplexy), drug abuse, alcohol and opiate withdrawal, a reduced level of growth hormone, anxiety, analgesia, effects in certain neurological disorders such as Parkinson""s Disease, depression, certain endocrine disturbances and tissue protection following hypoxia/anoxia such as in stroke or myocardial infarction, or for an increased level of intracranial pressure or the like. The present invention particularly relates to the field of pharmaceutical production of microbiologically resistant and chemically stable preparations or solutions of gamma-hydroxybutyrate (GHB), also known as 4-hydroxybutyrate, and the sodium salt of GHB (sodium oxybate) and other salts such as magnesium, ammonium and calcium, e.g.
II. Description of Related Art
GHB is an endogenous compound with hypnotic properties that is found in many human body tissues. GHB is present, for example, in the mammalian brain and other tissues. In brain the highest GHB concentration is found in the hypothalamus and basal ganglia and GHB is postulated to function as a neurotransmitter (Snead and Morley, 1981). The neuropharmacologic effects of GHB include increases in brain acetylcholine, increases in brain dopamine, inhibition of GABA-ketoglutarate transaminase and depression of glucose utilization but not oxygen consumption in the brain. GHB is converted to succinate and then metabolized via the Krebs cycle. Clinical trials have shown that GHB increases delta sleep and improves the continuity of sleep (Ladinsky et al., 1983; Anden and Stock, 1973; Stock et al., 1973; Laborit, 1973; Lapierre et al., 1988; Lapierre et al., 1990; Yamda et al., 1967; Grove-White and Kelman, 1971; Scharf, 1985).
GHB has typically been administered in clinical trials as an oral solution (Lee, 1977; Mamelak, 1977; Hoes, 1980; Scharf, 1985; Scrima, 1990; Gallimberti, 1992; Series, 1992; Lammers, 1993). GHB treatment substantially reduces the signs and symptoms of narcolepsy, i.e. daytime sleepiness, cataplexy, sleep paralysis and hypnagogic hallucinations. In addition, GHB increases total sleep time and REM sleep, and it decreases REM latency (Mamelak et al, 1973; Yamada et al., 1967; Bedard et al., 1989), reduces sleep apnea (Series et al, 1992; Scrima et al., 1987), and improves general anesthesia (Hasenbos and Gielen, 1985).
GHB has several clinical applications other than narcolepsy and sleep disorders. GHB has been reported to reduce alcohol craving, the number of daily drinks consumed, and the symptoms of alcohol withdrawal in patients (Gallimberti et al., 1989; Gallimberti et al., 1992; Gessa et al., 1992). GHB has been used to decrease the symptoms of opiate withdrawal. including both heroin and methadone withdrawal (Gallimberti et al, 1994; Gallimberti et al., 1993). It has analgesic effects that make it suitable as a pain reliever (U.S. Pat. No. 4,393,236). Intravenous administration of GHB has been reported to reduce intracranial pressure in patients (Strong, A. 1984). Also, administration of GHB was reported to increase growth hormone levels in patients (Gerra et al, 1994; Oyama et al., 1970).
A good safety profile for GHB consumption, when used long term for treatment of narcolepsy, has been reported. Patients have been safely treated for many years with GHB without development of tolerance (Scharf, 1985). Clinical laboratory tests carried out periodically on many patients have not indicated organ or other toxicities (Lammers, 1993; Scrima, 1990; Scharf, 1985; Mamelack, 1977; Mamelak, 1979; Gallimberti, 1989; Gallimberti, 1992; Gessa, 1992). The side effects of GHB treatment have been minimal in incidence and degree of severity, though they include sleepwalking, enuresis, headache, nausea and dizziness (Broughton and Mamelak, 1979; Mamelak et al., 1981; Mamelak et al., 1977; Scrima et al., 1989; Scrima et al., 1990; Scharf et al., 1985).
The pharmacokinetics of GHB have been investigated in alcohol dependent patients (Ferrara et al., 1992) and in normal healthy males (Palatini et al., 1993) after oral administration. GHB possesses a rapid onset and short pharmacological effect (Ferrara et al., 1992; Palatine et al., 1993; Lee, C., 1977; van der Bogert; Gallimberti, 1989; Gallimberti, 1992; Lettieri and Fung, 1978; Arena and Fung, 1980; Roth and Giarman, 1966; Vickers, 1969; Lee, 1977). In alcohol dependent patients, GHB absorption into and elimination from the systemic circulation were fast processes. Virtually no unchanged drug could be recovered in the urine. There were preliminary indications that the pharmacokinetics of GHB might be non-linear or dose-dependent (Ferrara et al., 1992). In the healthy volunteers study, the pharmacokinetics of three rising GHB doses (12.5, 25, and 50 mg/kg) were investigated. These findings indicate that both the oral absorption and elimination processes of GHB were capacity-limited though the degree of dose dependency was moderate (Palatini et al., 1993).
Organic salts and amides of GHB have been produced to reduce the physiological side effects of GHB (U.S. Pat. No. 5,380,937). Magnesium and calcium salt have been produced to reduce the hygroscopic nature of GHB or powdered forms (U.S. Pat. No. 4,393,236; British Patent No. 922,029). However, problems with the storage of GHB solutions still exist. GHB degrades into gamma-butyrolactone (GBL) and possibly other degradants in solution depending upon the pH and other factors. Also, the contamination by microorganisms in GHB solutions rapidly surpass acceptable limits, and preservatives can adversely affect the pH and thus, GHB""s stability. As a chronically used product which requires high levels of drug, the volume of a non-concentrated product creates cost and handling issues. Thus, there is an immediate need for effective solutions of GHB that are stable to biological or chemical degradation.
The present invention overcomes deficiencies in the prior art by providing compositions of GHB in an aqueous medium that are resistant to microbial growth. These compositions are also resistant to the uncontrolled degradation of GHB into GBL or other substances. The compositions of the present invention are stable compositions of GHB that improve shelf-life, and provide a titratable formulation of GHB for easy dose measurement. In addition, the concentrated solutions embodied in this invention reduce shipping and storage requirements and allow patients to carry more drugs for their convenience. The present invention provides methods to treat a number of conditions treatable by GHB, referred to herein as xe2x80x9ctherapeutic categories.xe2x80x9d Therapeutic categories for the present invention include, but are not limited to, sleeping disorders, drug abuse, alcohol and opiate withdrawal, a reduced level of growth hormone, anxiety, analgesia, effects in certain neurological disorders, such as Parkinson""s Disease, depression, certain endocrine disturbances and tissue protection following hypoxia/anoxia such as in stroke or myocardial infarction, or an increased level of intracranial pressure or other conditions treatable with GHB.
The invention first provides a pharmaceutical composition of GHB rendered chemically stable and/or resistant to microbial growth in an aqueous medium. Preferred GHB salts of the present invention include sodium, ammonium and calcium. As used herein in certain embodiments, xe2x80x9cstablexe2x80x9d may mean resistant to degradation of GHB into its known or unknown decomposition elements. The level of GBL that is acceptable can be up to 0.1% of the formulation as per the ICH guidelines for shelf-life determination, As used herein in certain embodiments, xe2x80x9cresistant to microbial growthxe2x80x9d or xe2x80x9cresistant to microbial challengexe2x80x9d means that the formulations meet the criteria set by the Food and Drug Administration and the U.S. Pharmacopoeia for products made with aqueous bases or vehicles, which for bacteria means not less than a 1.0 log reduction from the initial count at 14 days, and no increase from the 14 days count at 28 days, and for yeast and molds, no increase from the initial calculated count at 14 and 28 days. As used herein in certain embodiments, an xe2x80x9caqueous mediumxe2x80x9d may mean a liquid comprising more than about 50% water. In certain preferred embodiments, an xe2x80x9caqueous mediumxe2x80x9d may be a solution, suspension, gel or emulsion of GHB, with a solution of GHB being most preferred. Preferred gels are thixotropic gels. Compositions that are resistant to microbial growth are created by dissolving or mixing GHB in an aqueous medium to a concentration or content of greater than of about 150 mg/ml GHB to the maximal solubility of GHB. The solubility of GHB is up to about 750 mg/ml at room temperature (20xc2x0 C. to about 25xc2x0 C.), however, heating the aqueous medium during preparation up to 100xc2x0 C. will increase GHB solubility to at least about 1000 mg/ml. A preferred concentration or content of GHB is about 500 mg/ml.
The amount of GHB that may be mixed or dissolved into an aqueous medium and still be resistant to microbial growth depends upon the pH of the aqueous medium. In certain embodiments the presence of a preservative may allow the amount of GHB contained in the compositions of the present invention to be increased and still maintain resistance to chemical degradation and/or microbial growth. In one embodiment of the present invention, the pH of the aqueous medium of the pharmaceutical composition is about 3 to about 10.
In a preferred embodiment, the pH of said aqueous medium is about 6 to about 7.5. The pH may be from about 3.0 to about 10.3, namely of about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6, about 3.7, about 3.8, about 3.9, about 4.0, about 4.1, about 4.2, about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about 4.8, about 4.9, about 5.0, about 5.1, about 5.2, about 5.3, about 5.4, about 5.5, about 5.6, about 5.7, about 5.8, about 5.9, about 6.0, about 6.1, about 6.2, about 6.3, about 6.4, about 6.5, about 6.6, about 6.7, about 6.8, about 6.9, about 7.0, about 7.1, about 7.2, about 7.3, about 7.4, about 7.5, about 7.6, about 7.7, about 7.8, about 7.9, about 8.0, about 8.1, about 8.2, about 8.3, about 8.4, about 8.5, about 8.6, about 8.7, about 8.8, about 8.9, about 9.0, about 9.1, about 9.2, about 9.3, about 9.4, about 9.5, about 9.6, about 9.7, about 9.8, about 9.9, about 10.0, about 10.1, about 10.2, or about 10.3, and all pH values between each of the listed pH values, of the aqueous media. This will produce a GHB composition that is resistant to microbial growth as defined by the test described herein. As used herein, the term xe2x80x9caboutxe2x80x9d generally means within about 10-20%.
These pH values will produce compositions resistant to microbial growth in an aqueous medium if the amount of GHB added, admixed, or dissolved is from above about 150 mg/ml to about 450 mg/ml, namely, above about 150 mg/ml, about 160 mg/ml, about 170 mg/ml, about 180 mg/ml, about 190 mg/ml, about 200 mg/ml, about 210 mg/ml, about 220 mg/ml, about 230 mg/ml, about 240 mg/ml, about 250 mg/ml, about 260 mg/ml, about 270 mg/ml, about 280 mg/ml, about 290 mg/ml, about 300 mg/ml, about 310 mg/ml, about 320 mg/ml, about 330 mg/ml, about 340 mg/ml, about 350 mg/ml, about 360 mg/ml, about 370 mg/ml, about 380 mg/ml, about 390 mg/ml, about 400 mg/ml, about 410 mg/ml, about 420 mg/ml, about 430 mg/ml, about 440 mg/ml, to about 450 mg/ml, and all amounts of GHB between the values listed.
At the medium to high end of the concentration or content of GHB that may be dissolved or mixed in the aqueous medium, the maximal pH that may be used is reduced at room temperature. This is shown in FIG. 1, a graphical presentation of acceptable formulation ranges. At a concentration or content of about 450 mg/ml GHB, the pH may be of about 3.9 to about 10.3. At a concentration or content of about 500 mg/ml GHB, the pH may be of about 4.75 to about 10.3. At a concentration or content of about 600 mg/ml GHB, the pH may be of about 6.1 to about 10.3. At a concentration or content of about 750 mg/ml GHB, the pH may be of about 7.0 to about 10.3. Of course, all pH and concentration or content values in between each of the listed pH and concentration or content values are encompassed by the invention.
Certain embodiments may be selected as sub-ranges from these values of GHB content and aqueous medium pH. For example, a specific embodiment may be selected as a content of about 170 mg/ml to about 440 mg/ml GHB in an aqueous medium, at a pH range of about pH 5.5 to about pH 8.7. Another example of how a range may be selected in an embodiment would be the selection of a content of about 155 mg/ml of GHB, which is a value between the above listed values, to a content of about 350 mg/ml of GHB, and the selection of a pH range of the aqueous medium, such as a pH range of about 8.87, which is a value between the listed pH values, to a pH of about 8.93, which is another value between the listed values of pH. A third example of ranges that may be selected for a specific embodiment would be selection of a single content or concentration of GHB, such as about 200 mg/ml of GHB, and the selection of a pH range, such as a pH of about 3.5 to about 8.2. A fourth example of ranges that may be selected for a specific embodiment would be selection of a content or concentration of GHB over a range, such as about 300 mg/ml to about 400 mg/ml, and the selection of a single pH value for the aqueous medium, such as a pH of about 3. Another example of a range selected for an embodiment may be the selection of a single content or concentration of GHB, such as 400 mg/ml GHB, and a single pH value of the aqueous medium, such as pH 7.7.
Other examples of how a range of an embodiment of GHB content or concentration may be selected include a range of GHB content or concentration from about 200 mg/ml to about 460 mg/ml GHB, encompassing the ranges for GHB described herein, and a range of pH for the aqueous medium may be from about pH 4.3 to about pH 7, encompassing ranges for GHB in an aqueous medium at room temperature described herein. Another example would be the selection of a range of GHB content or concentration from about 153 mg/ml to about 750 mg/ml, and a pH range of about 7 to about 9, encompassing ranges between the listed values of GHB content and pH described herein. An example may be the selection as a GHB concentration or content of about 170 mg/ml to about 640 mg/ml in an aqueous medium, at a pH range of about pH 6.5 to about pH 7.7. Another example of how a range may be selected in an embodiment would be a content or concentration of about 185 mg/ml of GHB, which is a value between the listed values, to a content or concentration of about 750 mg/ml of GHB, at a pH range of about 7.87, which is a value between the listed pH values, to a pH of about 8.91, which is another value between the listed values of pH. An additional example of ranges that may be selected for a specific embodiment would be a content or concentration of about 200 mg/ml of GHB at a pH of about 7 to about 8.2. Another example of ranges that may be selected for a specific embodiment would be a content or concentration of about 750 mg/ml to about 400 mg/ml at a pH of about 7. Another example of ranges that may be selected for a specific embodiment would be a content or concentration of about 300 mg/ml to about 750 mg/ml at a pH of about 8.5 to about 7. Another example of ranges that may be selected for a specific embodiment would be a content or concentration of about 400 mg/ml to about 600 mg/ml at a pH of about 9 to about 5.8. And so forth. Thus, all ranges of pH and GHB concentration or content that can be selected from the values herein and as would be understood by those of ordinary skill in the art, are encompassed by the present invention.
The chemical stability of GHB is affected by pH, with compositions of GHB in an aqueous medium with a pH below about 6 being less effective in maintaining the chemical stability of GHB. Compositions with a pH of greater than about 6.0 are preferred to produce chemically stable formulations of GHB. Thus, a preferred range to produce chemically stable GHB would be from about pH 6 to about pH 9. However, all concentrations or content of GHB in an aqueous medium, as described herein, and as would be understood by those of ordinary skill in the art, may be selected to produce compositions of the present invention.
Additionally, the ranges described above are for a composition at room temperature, which is defined herein as from about about 20xc2x0 C. to about 25xc2x0 C., namely, about 20xc2x0 C. about 21xc2x0 C., about 22xc2x0 C., about 23xc2x0 C., about 24xc2x0 C., to about 25xc2x0 C. Within the values and ranges of pH described above, the ranges of concentration or content of GHB may increase at temperatures greater than room temperature. Thus, the maximal content or concentration of GHB in an aqueous medium at a temperature of from about 26xc2x0 C. to about 100xc2x0 C., namely about 26xc2x0 C., about 27xc2x0 C., about 28xc2x0 C., about 29xc2x0 C., about 30xc2x0 C., about 31xc2x0 C., about 32xc2x0 C., about 33xc2x0 C., about 34xc2x0 C., about 35xc2x0 C., about 36xc2x0 C., about 37xc2x0 C., about 38xc2x0 C., about 39xc2x0 C., about 40xc2x0 C., about 41xc2x0 C., about 42xc2x0 C., about 43xc2x0 C., about 44xc2x0 C., about 45xc2x0 C., about 46xc2x0 C., about 47xc2x0 C., about 48xc2x0 C., about 49xc2x0 C., about 50xc2x0 C., about 51xc2x0 C., about 52xc2x0 C., about 53xc2x0 C., about 54xc2x0 C., about 55xc2x0 C., about 56xc2x0 C., about 57xc2x0 C., about 58xc2x0 C., about 59xc2x0 C., about 60xc2x0 C., about 61xc2x0 C., about 62xc2x0 C., about 63xc2x0 C., about 64xc2x0 C., about 65xc2x0 C., about 66xc2x0 C., about 67xc2x0 C., about 68xc2x0 C., about 69xc2x0 C., about 70xc2x0 C., about 71xc2x0 C., about 72xc2x0 C., about 73xc2x0 C., about 74xc2x0 C., about 75xc2x0 C., about 76xc2x0 C., about 77xc2x0 C., about 78xc2x0 C., about 79xc2x0 C., about 80xc2x0 C., about 81xc2x0 C., about 82xc2x0 C., about 83xc2x0 C., about 84xc2x0 C., about 85xc2x0 C., about 86xc2x0 C., about 87xc2x0 C., about 88xc2x0 C., about 89xc2x0 C., about 90xc2x0 C., about 91xc2x0 C., about 92xc2x0 C., about 93xc2x0 C., about 94xc2x0 C., about 95xc2x0 C., about 96xc2x0 C., about 97xc2x0 C., about 98xc2x0 C., about 99xc2x0 C., to about 100xc2x0 C., may be from about 750 to about 1 g/ml, namely to about 751 mg/ml, about 760 mg/ml, about 770 mg/ml, about 780 mg/ml, about 790 mg/ml, about 800 mg/ml, about 810 mg/ml, about 820 mg/ml, about 830 mg/ml, about 840 mg/ml, about 850 mg/ml, about 860 mg/ml, about 870 mg/ml, about 880 mg/ml, about 890 mg/ml, about 900 mg/ml, about 910 mg/ml, about 920 mg/ml, about 930 mg/ml, about 940 mg/ml, about 950 mg/ml, about 960 mg/ml, about 970 mg/ml, about 980 mg/ml, about 990 mg/ml, to about 1000 mg/ml. At temperatures below room temperature, the solubility of GHB may decrease, and compositions at lower temperature and solubility of GHB at the pH values and ranges described herein are also encompassed by the invention. Additionally, differences of atmospheric pressure may also increase or decrease the solubility of GHB within the ranges described, and embodiments of the invention with an increased or decreased content of GHB due to changes in pressure are also encompassed by the invention. Of course, it is understood that the present invention encompasses embodiments of GHB concentration or content in an aqueous medium at higher or lower temperature within the values described herein, such as about 980 mg/ml to about 200 mg/ml at 95xc2x0 C. GHB at a pH of about 9 to about 7.5. Or about 150 mg/ml GHB at about 17xc2x0 C. at about pH 6 to about pH 7. And so forth. Thus, all ranges of pH and GHB content that can be selected at various temperatures and pressures from the values above, and as would be understood by those of ordinary skill in the art, are encompassed by the present invention.
In certain other embodiments of the present invention, the pharmaceutical composition may comprise a pH adjusting or buffering agent. Such agents may be acids, bases, or combinations thereof. In certain embodiments, the acid may be an organic acid, preferably a carboxylic acid or alphahydroxy carboxylic acid. In certain other embodiments, the acid is selected from the group including, but not limited to, acetic, acetylsalicylic, barbital, barbituric, benzoic, benzyl penicillin, boric, caffeine, carbonic, citric, dichloroacetic, ethylenediaminetetra-acetic acid (EDTA), formic, glycerophosphoric, glycine, lactic, malic, mandelic, monochloroacetic, oxalic, phenobarbital, phenol, picric, propionic, saccharin, salicylic, sodium dihydrogen phosphate, succinic, sulfadiazine, sulfamerazine, sulfapyridine, sulfathiazole, tartaric, trichloroacetic, and the like, or inorganic acids such as hydrochloric, nitric, phosphoric or sulfuric, and the like. In a preferred embodiment, the acid is malic or hydrochloric acid. In certain other embodiments, the pH adjusting agent may be a base selected from the group including, but not limited to, acetanilide, ammonia, apomorphine, atropine, benzocaine, caffeine, calcium hydroxide, cocaine, codeine, ephedrine, morphine, papaverine, physostigmine, pilocarpine, potassium bicarbonate, potassium hydroxide, procaine, quinine, reserpine, sodium bicarbonate, sodium dihydrogen phosphate, sodium citrate, sodium taitrate, sodium carbonate, sodium hydroxide, theobromine, thiourea or urea. In certain other embodiments, the pH adjusting agent may be a mixture of more than one acid and/or more than one base. In other preferred embodiments, a weak acid and its conjugate base are used to form a buffering agent to help stabilize the composition""s pH.
In certain embodiments, the composition may contain one or more salts. A xe2x80x9csaltxe2x80x9d is understood herein to mean certain embodiments to mean a compound formed by the interaction of an acid and a base, the hydrogen atoms of the acid being replaced by the positive ion of the base. Various salts, including salts of GHB, are also encompassed by the invention, particularly as pH adjusting or buffering agents. Pharmaceutically acceptable salts, include inorganic acids such as, for example, hydrochloric or phosphoric acids, or such organic acids as malic, acetic, oxalic, tartaric, mandelic, and the like. Salts formed can also be derived from inorganic bases such as, for example, sodium, potassium, silicates, ammonium, calcium, or ferric hydroxides, and such organic bases as isopropylamine, trimethylamine, histidine, procaine and the like. Alkali met al salts, such as lithium, potassium, sodium, and the like may be used, preferably with an acid to form a pH adjusting agent. Other salts may comprise ammonium, calcium, magnesium and the like. In one embodiment, a salt of GHB comprising an alkali met al may be combined with an acid to create a composition that achieves the desired pH when admixed with an aqueous medium. In another embodiment, a weak base may be combined with GHB to create a composition that achieves the desired pH when admixed with an aqueous solution. Of course, other salts can be formed from compounds disclosed herein, or as would be known to one of ordinary skill in the art, and all such salts are encompassed by the invention.
In certain embodiments, excipients may be added to the invention. An xe2x80x9cexcipientxe2x80x9d as used herein shall mean certain embodiments which are more or less inert substances added as diluents or vehicles or to give form or consistency when the remedy is in a solid form, though they may be contained in liquid form preparations, e.g. syrups, aromatic powders, honey, and various elixirs. Excipients may also enhance resistance to microbial growth, and thus act as a preservative. Such excipients include, but are not limited to, xylitol, mannitol, lactose, starch, magnesium stearate, sodium saccharine, cellulose, cellulose derivatives, magnesium carbonate and the like.
In certain embodiments, the pharmaceutical composition may contain a preservative. A xe2x80x9cpreservativexe2x80x9d is understood herein to mean certain embodiments which are substances added to inhibit chemical change or microbial action. Such preservatives may include, but are not limited to, xylitol, sodium benzoate, methylparaben, propyl gallate BP, sorbic acid, chlorobutanol, dihydroacetic acid, monothioglycerol, potassium benzoate, propylparaben, benzoic acid, benzalkonium chloride, alcohol, benzoic acid, benzalkonium chloride, benzethonium chloride, benzyl alcohol, butylparaben, cetylpyridinium chloride, ethylenediamine, ethylpareben, ethyl vanillin, glycerin, hypophophorus acid, methylparaben, phenol, phenylethyl alcohol, phenymercuric nitrate, propylparaben, sassafras oil, sodium benzoate, sodium propionate, thimerosal and potassium sorbate. Preferred preservatives may be selected from the group comprising, but not limited to, xylitol, sodium benzoate, methylparaben, propylparaben and potassium sorbate. Xylitol is particularly preferred in certain compositions of the invention, because it acts as an preservative and a sweetener, is a caries preventative, is less laxative than other sweeteners, and is recommended for diabetics.
In certain embodiments, the pharmaceutical composition may also contain an antioxidant. An xe2x80x9cantioxidantxe2x80x9d is understood herein to mean certain embodiments which are substances that inhibits oxidation. Such antioxidants include, but are not limited to, asocrbyl palmitate, butylated hydroxyanisole, butylated hydroxytoluene, potassium metabisulfite, sodium metabisulfite, anoxomer and maleic acid BP.
In certain embodiments, the pharmaceutical composition may also contain a flavoring agent. A xe2x80x9cflavoring agentxe2x80x9d is understood herein to mean certain embodiments which are substances that alters the flavor of the composition during oral consumption. A type of xe2x80x9cflavoring agentxe2x80x9d would be a sweetener. Preferred sweeteners or flavoring agents would be microbially non-metabolizable. Especially preferred sweeteners or flavoring agents would be carbohydrates such as xylitol and sorbitol. Such flavoring agents include, but are not limited to, acacia syrup, anethole, anise oil, aromatic elixir, benzaldehyde, benzaldehyde elixir-compound, caraway, caraway oil, cardamom oil, cardamom seed, cardamom spirit, cardamom tincture-compound, cherry juice, cherry syrup, cinnamon, cinnamon oil, cinnamon water, citric acid, citric acid syrup, clove oil, coca, coca syrup, coriander oil, dextrose, eriodictyon, eriodictyon fluidextract, eriodictyon syrup-aromatic, ethyl acetate, ethyl vanillin, fennel oil, ginger, ginger fluidextract, ginger oleoresin, glucose, glycerin, glycyrrhiza, glycyrrhiza elixir, glycyrrhiza extract, glycyrrhiza extract-pure, glycyrrhiza fluidextract, glycyrrhiza syrup, honey, non-alcoholic elixir, lavender oil, citrus extract or oil, lemon oil, lemon tincture, mannitol, methyl salicylate, nutmeg oil, orange-bitter-elixir, orange-bitter-oil, orange flower oil, orange flower water, orange oil, orange peel-bitter, orange-peel-sweet-tincture, orange spirit-compound, compound, orange syrup, peppermint, peppermint oil, peppermint spirit, peppermint water, phenylethyl alcohol, raspberry juice, raspberry syrup, rosemary oil, rose oil, rose water, saccharin, saccharin calcium, saccharin sodium, sarsaparilla syrup, sorbitol solution, spearmint, spearmint oil, sucrose, syrup, thyme oil, tolu balsam, tolu balsam syrup, vanilla, vanilla tincture, vanillin or wild cherry syrup.
Salts, excipients, pH adjusting agents such as acids, bases and buffering agents, flavoring agents, and other agents that may be combined with the compositions of the present invention, or may be used to prepare the compositions of the present invention, are well known in the art, (see for example, xe2x80x9cRemington""s Pharmaceutical Sciencesxe2x80x9d 8th and 15th Editions, and Nema et al., 1997, incorporated herein in their entirety), and are encompassed by the invention.
In certain other embodiments, the pharmaceutical composition comprises GHB, a pH adjusting or buffering agent, and an aqueous medium, wherein the components are admixed (sequentially or simultaneously) to prepare said pharmaceutical composition. The pH adjusting or buffering agent and aqueous medium may be any described herein.
The invention also provides a method of preparing a chemically stable and microbial growth-resistant pharmaceutical composition for the treatment of a condition responsive to GHB, comprising admixing GHB and a pH-adjusting or buffering agent in an aqueous medium. In certain embodiments, the method of preparing the pharmaceutical composition further comprises admixing a preservative with the pharmaceutical composition. Other components, such as flavoring agents, salts, and the like, may be added to the composition. The pH adjusting or buffering agent, aqueous medium, preservative, flavoring agents, salts, or other ingredient may be any described herein.
In certain other embodiments, the method of preparing the pharmaceutical composition comprises admixing GHB, a pH adjusting or buffering agent, and an aqueous medium soon before administration to a patient suspected of having a condition responsive to GHB.
The invention also provides a method of treating any therapeutic category of disorder responsive to GHB, comprising administering to a patient suspected of having such a condition a therapeutic amount of a pharmaceutical composition comprising chemically stable GHB (e.g. 1-10 gms.) in an aqueous medium resistant to microbial growth. In certain embodiments, the method of treating a condition responsive to GHB comprises a patient taking a first dosage of from about 0.1 g to about 10 g, namely about 0.1, about 0.2 about 0.3 about 0.4, about 0.5, about 0.6, about 0.7, about 0.8, about 0.9, about 1.0, about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9, about 2.0, about 2.1, about 2.2, about 2.3, about 2.3, about 2.4, about 2.5, about 2.6, about 2.7, about 2.8, about 2.9, about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6, about 3.7, about 3.8, about 3.9, about 4.0, about 4.1, about 4.2, about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about 4.8, about 4.9, about 5.0, about 5.1, about 5.2, about 5.3, about 5.4, about 5.5, about 5.6, about 5.7, about 5.8, about 5.9, about 6.0, about 6.1, about 6.2, about 6.3, about 6.4, about 6.5, about 6.6, about 6.7, about 6.8, about 6.9, about 7.0, about 7.1, about 7.2, about 7.3, about 7.4, about 7.5, about 7.6, about 7.7, about 7.8, about 7.9, about 8.0, about 8.1, about 8.2, about 8.3, about 8.4, about 8.5, about 8.6, about 8.7, about 8.8, about 8.9, about 9.0, about 9.1, about 9.2, about 9.3, about 9.4, about 9.5, about 9.6, about 9.7, about 9.8, about 9.9, to about 10 grams of GHB, or as needed by the patient as would be recognized by one of skill in the art. Of course, it will be understood that all values in between those listed, such as 9.45 grams, 6.32 grams, etc. may be administered, and those values are encompassed well. In preferred embodiments, the first dose is administered within an hour of sleep. In preferred embodiments, a second dose of GHB within the values described above may be administered. This second dose is administered preferably within about 2.0 to about 5.0 hrs, namely about 2.0, about 2.1, about 2.2, about 2.3, about 2.3, about 2.4, about 2.5, about 2.6, about 2.7, about 2.8, about 2.9, about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6, about 3.7, about 3.8, about 3.9, about 4.0, about 4.1, about 4.2, about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about 4.8, about 4.9, to about 5.0 hours after the first dose, though it may be administered at a time outside of the preferred range.
In certain embodiments, a second pharmaceutical may be administered with the composition of GHB. Such a second pharmaceutical may be e.g., a stimulant administered within the same 24 hour period as the first dose of GHB. The stimulant may be, e.g., but not limited to, methylphenidate or pemoline to counter the residual effects of GHB treatment during periods of wakefulness. In certain embodiments, the method of treating a sleep disorder may include the discontinuation of other second pharmaceuticals used to control a sleep disorder. Such second pharmaceuticals may include, but are not limited to, a tricyclic antidepressant.
In certain embodiments, the invention provides a method of treating any appropriate therapeutic category of disorder, by administration of GHB compositions of the present invention as described above for the treatment of sleep disorders. When GHB is used in methods of treating any therapeutic category of disorder, the GHB composition of the present invention may be mixed with the aqueous medium, and optionally pH adjusting or buffering agent or other additives, by the patient or administrator soon before consumption. The patient may prepare the composition within a few minutes to hours before administration. Alternatively, one or more of the components may be premixed for ready use. The components of the GHB composition of the present invention, GHB, an aqueous medium, pH adjusting or buffering agent, excipients, preservatives, flavoring agents, and/or other components or additives may be stored in a container means suitable to aid preservation. Preferably, the container means is in the form of a set. A xe2x80x9csetxe2x80x9d as used herein certain embodiments is one or more components of the composition packaged in a container or other suitable storage means.
The present invention also provides a set for the treatment of a condition responsive to GHB comprising, in suitable storage means, GHB and a pH adjusting or buffering agent. In certain embodiments, the GHB and the pH adjusting or buffering agent are separately packaged. In certain other embodiments the GHB and the pH-adjusting or buffering agent may be mixed. The set may contain an aqueous medium. In certain other embodiments, at least one component selected from the group including, but not limited to, GHB, the pH-adjusting or buffering agent and/or an aqueous medium is separately packaged. In certain other embodiments, at least two of the components selected from the group comprising GHB, a pH adjusting or buffering agent and an aqueous medium are mixed together. In some embodiments, the set further contains a preservative. Such a set may have one, two, or more components from the group comprising GHB, a pH-adjusting or buffering agent, an aqueous medium or a preservative packaged separately. Such a set may have two or more components mixed together. Thus, both liquid and dry formulations of GHB and other components may be packaged in a set for mixing before administration, or one or more components may be premixed and packaged together with other components, or all the components may be premixed and packaged in a set.
It is understood that the compositions of the present invention, including those in a set, may be dispersed in a pharmaceutically acceptable carrier solution as described below. Such a solution would be sterile or aseptic and may include water, co-solvent vehicle buffers, isotonic agents, pharmuceutical aids or other ingredients known to those of skill in the art that would cause no allergic or other harmful reaction when administered to an animal or human subject. Therefore, the present invention may also be described as a pharmaceutical composition of GHB with increased stability in a pharmaceutically acceptable carrier solution.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Also as used herein, the term xe2x80x9caxe2x80x9d xe2x80x9canxe2x80x9d or xe2x80x9cthexe2x80x9d is understood to include the meaning xe2x80x9cone or morexe2x80x9d. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described.